JPH0978430A - Production of antibacterial long-fiber nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production of a long-fiber nonwoven fabric without clogging of a pack filter and thread breaking during a melt spinning process, excellent in operativity and spinnability and, at the same time, in flexibility and antibacterial properties. SOLUTION: This production method of an antibacterial long-fiber nonwoven fabric is to mix a resin composition comprising a thermoplastic olefin-based polymer containing zirconium phosphate carrying silver having 0.1-1.0μm average particle size with a resin composition comprising a thermoplstic olefin-based resin containing no pigment, heat and melt the mixture, adjust the content of zirconium phosphate carrying silver to 0.1-3.0wt.% based on the total weight and extrude and spin the adjusted mixture from a large number of spinneret. The resin composition containing zirconium phosphate carrying silver having dispersion of fisheyes with >100μm diameter in 0-6 fisheyes/m<2> when measured the surface of a film by a fisheye measuring device after forming the film having 30μm thickness by a T die at 230C can be used for this purpose.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an antibacterial long-fiber nonwoven fabric. More specifically, the present invention, when the thermoplastic resin is heated and melt-spun, there is almost no yarn breakage and clogging in the pack filter, and excellent flexibility,
Since it has antibacterial properties, it can be used in a wide range of fields such as medical and sanitary materials and general industrial materials, and is especially suitable as a surface material for sanitary materials such as disposable diapers and sanitary napkins. The present invention relates to a manufacturing method of.

[0002]

2. Description of the Related Art Nonwoven fabrics have traditionally been used for medical and hygiene materials,
Widely used for general industrial materials, civil engineering and construction materials, etc.
In particular, in recent years, non-woven fabrics are rapidly increasing in use in applications such as diapers, wipers, sanitary napkins, hospital gowns and sheets, etc., which are in direct contact with human skin. Therefore, the non-woven fabrics used for these purposes are required to hygienically suppress the generation and growth of bacteria and mold and eliminate the bad odor generated by these. Conventionally, as materials that impart antibacterial and antifungal properties to non-woven fabrics, for example, metal ions such as silver, copper, and zinc, which are said to be inorganic antibacterial agents, and organic silicon-based fourth agents, which are said to be organic antibacterial agents There are secondary ammonium salts and chitosan.

Japanese Patent Laid-Open No. 54-147220 discloses an acrylonitrile fiber containing a copper compound obtained by producing a coagulated yarn by using a mixture of copper or a copper compound and an acrylonitrile polymer as a spinning solution. Fiber web consisting of cellulosic natural fibers and anti-synthetic fibers,
Nonwoven fabric using chitosan as an interfiber binder
No. 27165. Furthermore, the particle size is 1
A non-woven fabric composed of regenerated cellulose fibers containing finely regenerated chitosan having a size of 0 μm or less is disclosed in JP-A-5-18694.
No. 5 discloses this. JP-A-59-133235
The publication discloses a zeolite particle-containing polymer which is composed of zeolite-based solid particles and an organic polymer, and at least a part of the zeolite-based solid particles retains metal ions having a bactericidal action. , Which contains zeolitic solid particles holding metal ions having a bactericidal action,
That is, the organic polymer is added and mixed at an arbitrary stage before molding. However, these have the drawbacks that the steps of the fiber manufacturing method are complicated and the antibacterial agent falls off during use.

Conventionally, a thermoplastic synthetic resin has been melted as a method for producing a continuous filament by melting and spinning a thermoplastic resin into a continuous filament, which is made by filament-forming a non-woven fabric with antibacterial property. It is known to knead and carry an antibacterial agent in the thermoplastic resin before spinning or during melt spinning. JP-A-5-51816 discloses a phosphate-type layered compound having an average particle diameter of 5 microns or less and containing a metal ion having antibacterial properties,
Polymerization of a polymer is carried out by using an antibacterial fiber composed of a thermoplastic polymer containing a liquid polyester compound having a melting point lower than 10 ° C. and a viscosity at 25 ° C. of 10 poise or more, and a mixture composed of the two kinds of compounds. There is disclosed a method for producing an antibacterial fiber which is added into the polymer melt fluid after completion and kneaded and then discharged from a discharge hole to form a fiber.

However, this method has the effect of suppressing the shortening of the life of the pack due to the clogging of the solid particles that have fallen off in the pack filter, but the solid particles are not uniformly dispersed in the synthetic resin. In addition, there is a problem that the melt spinning is not satisfactory because the yarn breakage frequently occurs during the hot melt spinning. Then, the quality of the dispersibility due to the solid particles is determined only by actually using such a resin, so if the resin has a poor dispersibility, the operation is stopped, and the defective product generated from the removal of the resin is If the disposal is included, a great deal of damage will occur. Therefore,
When a thermoplastic resin in which an antibacterial agent of solid particles is kneaded is heated and melt-spun to form a filament, and a nonwoven fabric is collected and collected, it is extremely important to select a resin that can be continuously used. It is strongly desired to embody a manufacturing method using such a resin.

[0006]

In view of the present situation, the present inventors knead fine particles of an inorganic compound having an antibacterial property with a thermoplastic resin, heat-melt the fine particle-containing thermoplastic resin, and spin it. As a filament, the filament is collected to form a web, and then hot embossing is applied to the method for producing a non-woven fabric. As a result, the average particle size, content rate, and dispersion of the kneading antibacterial agent are determined. The present invention has been completed based on the finding that an antibacterial long-fiber non-woven fabric can be easily produced without causing yarn breakage during melt spinning by reliably controlling the properties. Therefore, an object of the present invention is to provide an antibacterial long-fiber non-woven fabric excellent in flexibility and antibacterial property without problems such as shortening of pack life due to pack filter clogging during melt spinning process and yarn breakage during drawing process. It is to provide a method capable of manufacturing.

[0007]

Means for Solving the Problem The present invention relates to a thermoplastic olefin polymer containing 10 to 30% by weight based on the total weight of zirconium phosphate supporting silver having an average particle size of 0.1 to 1.0 μm. And a resin composition made of a thermoplastic olefin polymer containing no pigment, and the mixture is heated and melted, and the content of zirconium phosphate carrying silver is 0.1 to 100% by total weight. Adjusted to 3.0% by weight, then extruded and spun from a number of spinnerets, and the spun continuous filament filaments are drawn by an ejector while being drawn by high-speed high-pressure air, opened, and spread on a support surface for collection. In the method of producing an antibacterial long-fiber nonwoven fabric by forming a web by collecting the resin composition containing the zirconium phosphate carrying silver, 230 In and T-die molding, and formed into a film having a thickness of 30 [mu] m, the film surface, when measured with fisheye measuring machine, the variance of the range number of fisheyes 0-6 ² per 1m of diameter exceeding 100μm A method for producing an antibacterial long-fiber non-woven fabric, which is characterized by using a material having properties.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A compound that can be used as an antibacterial agent in the present invention is a phosphate-based compound such as zirconium phosphate, titanium phosphate, tin phosphate, etc. Zirconium phosphate is then preferred. Examples of metal ions having antibacterial properties include silver, copper, zinc, tin, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, and chromium. Particularly, silver, copper and zinc ions are preferable. Most preferred is silver, which has high antibacterial properties and excellent safety. The average particle size of the antibacterial agent used in the present invention is in the range of 0.1 to 1.0 μm, preferably 0.3 to 0.9 μm. Average particle size is 0.1μ
When it is less than m, the existence probability of the antibacterial agent existing on the surface of the long fibers constituting the long fiber non-woven fabric becomes small, and sufficient antibacterial property cannot be exhibited. If the content is increased in order to exhibit sufficient antibacterial property, poor dispersion of the antibacterial agent will occur, and the pack life will be shortened due to clogging of the pack filter and yarn breakage during melt spinning will occur. On the other hand, when the average particle size of the antibacterial agent exceeds 1.0 μm, the antibacterial agent is likely to drop off, the pack life is shortened due to pressure increase due to clogging of the pack filter during melt spinning, and the spun filament is spun at high speed and high pressure. In this case, yarn breakage is likely to occur during drawing, making it difficult to use.

The above-mentioned antibacterial agent is added to the thermoplastic resin composition in an amount of 10 to 35% by weight, preferably 20 to 25% by weight, based on the total weight of the thermoplastic resin composition. A resin stabilizer is added, and this is kneaded by a conventional kneading means, preferably a twin-screw kneading extruder or the like to obtain a master batch pellet made of a resin composition containing an antibacterial agent. Next, in actual use, the masterbatch pellets containing the antibacterial agent and the same type of thermoplastic resin composition containing no antibacterial agent are mixed in an extruder for hot melt spinning, and melt-spun. The filament is spun out, and the content of the antibacterial agent is adjusted to be in the range of 0.1 to 3.0% by weight based on the total weight of the filament. When the content of the antibacterial agent in the masterbatch pellets is less than 10% by weight, the number of times the masterbatch pellets are manufactured increases, which is disadvantageous in terms of economy, and conversely, the content exceeds 35% by weight. And mixing such a masterbatch pellet and a thermoplastic resin composition containing no antibacterial agent, when heated and melt-spun, the amount of the masterbatch pellet used becomes too small, so long fibers obtained after mixing It is not preferable because the antibacterial agent cannot be dispersed sufficiently uniformly in the filament. When the masterbatch pellets are mixed with a thermoplastic resin composition containing no antibacterial agent, and then the long fiber filaments formed by heating and melt spinning are used as a non-woven fabric when the content of the antibacterial agent is less than 0.1% by weight. At this time, the antibacterial property is not sufficiently exhibited, and when the content exceeds 3.0% by weight, the antibacterial effect is saturated and reaches a ceiling, and the content higher than this is not preferable from the economical aspect.

23 of the masterbatch pellets of the thermoplastic resin composition containing the antibacterial agent obtained as described above are prepared.
T-die molding was carried out at a temperature of 0 ° C. under an extruder and molding conditions of the specifications shown in Table 1 to form a film having a thickness of 30 μm ± 3 μm, and the diameter existing on the surface of the film was 10 μm.
The number of fish eyes exceeding 0 μm is measured with a fish eye measuring machine (Laser Eye, manufactured by Yasukawa Electric Co., Ltd.). The fish eye referred to in the present invention is defined as a scratch having a fisheye-like shape observed on the surface of the film formed as described above. In the present invention, the number of fish eyes of the masterbatch pellets measured as described above is in the range of 0 to 6 in terms of the average number (rounded to one decimal place) of 10 measurements per 1 m ^{2 of} the film surface. A masterbatch pellet having antibacterial agent dispersibility is mixed with a thermoplastic resin composition containing no antibacterial agent, and the mixture is used to extrude from a die of an extruder.

[0011]

[Table 1]

In this way, the melted and melt-spun fibers are taken out while the spun long filament filaments are drawn by an ejector while being drawn with high-speed and high-pressure air, applied to a collision plate to be frictionally charged, and opened by the repulsive force due to the generated charges. Make it fine. In this case, corona discharge treatment may be performed as a charging method. A large number of filament filaments that have been uniformly spread,
A web is obtained by collecting and depositing on a support for collection.
When the average number of fish eyes of the masterbatch pellets exceeds 6 / m ² , if the pellets of this resin composition are used, clogging of the pack filter is likely to occur in the process of heat melt spinning, and the pack life is shortened. And the problem of yarn breakage occurs during the drawing process, which is not suitable.

The thermoplastic resin composition used in the present invention is easy to control the water content, has a low resin unit price, and is highly resistant to acids and alkalis, and therefore polypropylene, high-density polyethylene or the like is considered, but is preferable. Is a thermoplastic olefin polymer composed of polypropylene. This polyolefin-based polymer resin composition has a JI
190 measured by the method described in SK 7210
The melt flow rate under the conditions of ° C and a load of 2.16 kg is 20 to 70 g / 10 minutes, preferably 30 to 60 g /
10 minutes. The melt flow rate of this resin is 20g
If it is less than / 10 minutes, it is necessary to raise the melt spinning temperature, which not only causes an increase in cost, but also the produced sheet becomes hard and the texture is lowered, which is not preferable. On the contrary, if the melt flow rate exceeds 70 g / 10 minutes,
It is not preferable because the number of yarn breakages increases during drawing with high-speed, high-pressure air by an ejector.

The fineness of the long fibers used in the present invention is from 1 to
It is in the range of 5 denier. If the fineness of the long fibers is less than 1 denier, it may be difficult to stably spin the long fibers. On the contrary, if the fineness of the long fibers exceeds 5 denier, the fiber diameter becomes too thick, and the obtained long fibers are obtained. The non-woven fabric may become hard and the texture may be deteriorated, which may cause a problem. In the present invention, a web composed of a large number of filament filaments accumulated on a support for collection is used to maintain the shape of a sheet and impart self-strength of fibers by thermocompression bonding at regular intervals for the purpose of imparting strength. A fusion zone is provided. In this self-fusing area, a web composed of a large number of filament filaments accumulated on a support for collection is passed through an embossing roll consisting of a heated concavo-convex roll and a smooth roll, and the web part corresponding to the convex part is formed. Are obtained by fusing.

In this case, the roll temperature is set to 5 to 50 ° C., preferably 5 to 40 ° C. lower than the melting point of the resin forming the long fibers to be used. If the difference between the roll temperature and the melting point of the resin is less than 5 ° C., the fibers may adhere to the roll during thermocompression bonding with the roll, which may cause manufacturing troubles. Conversely, the difference between the roll temperature and the melting point of the resin may be 50%. When the temperature exceeds ℃, the formation of the self-fusing part becomes insufficient, and not only the strength of the non-woven fabric is significantly lowered, but also inconvenience such as severe feathering may occur. When the thermocompression-bonding treatment is performed by a pair of thermocompression-bonding rolls including an uneven roll and a smooth roll, the linear pressure is 10 to 80 kg / cm, preferably 20 to 60 kg / cm. Linear pressure is 10kg /
If it is less than 80 cm, the formation of the self-bonding area by thermocompression bonding may be insufficient, and if it exceeds 80 kg / cm,
The self-fusing area may become a film and the texture of the nonwoven fabric may be impaired. As a method of forming a self-bonding area, a web composed of a group of continuous filament filaments accumulated is introduced between an uneven roll and an ultrasonic horn, and subjected to ultrasonic treatment to obtain a convex portion of the uneven roll. It is also possible to form a spot fusion-bonded portion corresponding to.

In the present invention, the area of the self-fusing zone is within the range of 0.03 to ⁴ mm ² . If the area of this self-bonding area is less than 0.03 mm ² , the strength of the nonwoven fabric may be insufficient.
If it exceeds mm ² , the nonwoven fabric may become excessively hard.
The total area of the self-bonding area is 2 to 2 of the total area of the nonwoven fabric.
It is preferably within the range of 0%. If the total area of the self-bonding regions is less than 2%, the strength of the nonwoven fabric may be insufficient, and if the area of the self-bonding regions exceeds 20%, the nonwoven fabric may become excessively hard. The basis weight of the long-fiber nonwoven fabric in the present invention is preferably in the range of 5 to 100 g / m ² . When the basis weight is less than 5 g / m ² , it is difficult to stably produce the long-fiber nonwoven fabric because the basis weight is too low, and conversely, when the basis weight exceeds 100 g / m ² , the feel of the sheet decreases, which is preferable. Absent.

According to the present invention, a polyolefin containing an antibacterial agent is heated and melt-spun to form a continuous filament filament group, which is drawn with a high-speed high-pressure air while being drawn, opened, collected and accumulated to form a web. It is a method of producing a long fiber nonwoven fabric by forming and subjecting this web to thermocompression bonding treatment,
Even if it contains an antibacterial agent, there is no yarn breakage during heat melt spinning, and there is no clogging in the pack filter, so it is possible to efficiently produce a long-fiber nonwoven fabric having excellent antibacterial agent dispersibility. The antibacterial long-fiber non-woven fabric obtained as described above has excellent flexibility, texture and antibacterial property, and is variously processed as necessary to be used as a hygiene material, medical base material, clothing base material, household use. Used as a base material, industrial base material, etc.

[0018]

[Examples] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In the examples and comparative examples,% means% by weight unless otherwise specified.

Example 1 An antibacterial agent comprising silver supported on zirconium phosphate having an average particle size of 0.9 μm (Novalon AG-300, manufactured by Toagosei Co., Ltd.)
Was added to polypropylene having a melt flow rate of 50 g / 10 min and kneaded with a twin-screw kneading extruder to prepare polypropylene masterbatch pellets containing an antibacterial agent. The masterbatch pellets were melted by an extruder at 230 ° C. under the film forming conditions shown in Table 1 and T-die formed to form a film having a thickness of 30 μm. The film was measured with a fish eye measuring device (Laser Eye, Yasukawa Electric). The number of fish eyes having a diameter of more than 100 μm was measured by a manufacturing company, and it was 3 pieces / m ² . Next, this masterbatch pellet was mixed with the same polypropylene containing no antibacterial agent as described above to adjust the content of the antibacterial agent to 0.5% by weight. It is heated and melted by a method of extruding from a fine hole of an extrusion spinning machine, spun, and the spun continuous filament filaments are drawn by an ejector while being drawn with high-speed high-pressure air, opened, opened, and collected for running. A web was formed by collecting and depositing on the surface of the support. The fineness of this long fiber was 2.1 denier.

Next, the long fiber filament group is formed.
Of the uneven roll and the smooth roll that heated the web to 150 ℃
Introduced in between, and fuse the part corresponding to the convex part of the concavo-convex roll
By doing so, the basis weight is 23 g / m²Manufacture of long-fiber non-woven fabric
did. The roll linear pressure at this time was 35 kg / cm, which was obtained.
Area of self-bonding area of long fiber non-woven fabric is 0.12m
m ², The total area of self-bonding area is the total surface area of non-woven fabric
It was 4.2 area%. The resin composition is heated and melted and spun.
Check the clogged condition and spinnability of the pack filter when threading.
It evaluated by the method. (1) Pack filter clogging status If the filter is clogged with foreign matter, the pack
Filter pressure rises. If the dispersibility of the antibacterial agent is poor,
Dissolve the resin composition containing the antibacterial agent in the extrusion spinning machine.
The antibacterial agent clogs the filter during melt spinning, and
The pressure of the pack filter increases. So antibacterial
Pack fill when spinning a resin composition containing no agent
Pressure P₂Spinning a resin composition containing
Pack filter pressure P₁Difference (P₁-P₂)
The value of was used to evaluate the clogging situation. Difference value is 5kg / cm
²Anything over the range was considered to be in a bad condition. (2) Spinnability A resin composition containing an antibacterial agent is extruded and melt-spun by a spinning machine.
When spinning, the spinnability is determined by the number of yarn breakages that occur per hour.
evaluated. Good spinnability when the number of yarn breaks is 15 times / hour or less
I liked it.

The flexibility and sterilization rate of the fungus of the obtained long fiber non-woven fabric were measured by the following test methods to evaluate the quality. Test Method (1) Flexibility The softness of the nonwoven fabric was evaluated by touching it with the hands and evaluated according to the following 5 grades. 5 ・ Excellent flexibility. 4 ... Flexible. 3 ... Flexibility is normal. 2 ... Slightly inferior in flexibility. 1 ・ ・ Flexibility is extremely poor.

(2) Sterilization rate of bacteria Two types of bacteria, Klebsiella pneumoniae and Staphylococcus aureus, were used as bacterial species, and the sterilization rate was measured by the shake flask method. After adding a predetermined amount of the test bacterial solution to the Erlenmeyer flask, add 0.75 g of the sample piece, and use a list action type shaker to remove it.
Shake at 340 rpm for 1 hour. As a blank test, the same operation was repeated and tested for an Erlenmeyer flask to which no sample was added. After the test, the number of viable bacteria in the Erlenmeyer flask was measured, and then the sterilization rate was calculated by the formula (1). Sterilization rate,% = {(B−A) / B} × 100 (1) where A is the number of bacteria per 1 ml of the contents of the Erlenmeyer flask after shaking, and B is the content of the Erlenmeyer flask before shaking. The number of bacteria per 1 ml of the product is shown. The sterilization rate was tested using two types of bacteria, but both types had similar values, so the sterilization rate was evaluated by the average value of the results of the two types.

Example 2 A long-fiber nonwoven fabric was prepared and evaluated in the same manner as in Example 1 except that an antibacterial agent having an average particle size of 0.3 μm was used.

Example 3 Example 1 except that the content of the antibacterial agent was 0.1%.
A long fiber non-woven fabric was prepared in the same manner as above and evaluated.

Example 4 Example 1 except that the content of the antibacterial agent was 2.5%.
A long fiber non-woven fabric was prepared in the same manner as above and evaluated.

Example 5 A long fiber non-woven fabric was prepared in the same manner as in Example 1 except that polypropylene masterbatch pellets having the number of fish eyes having a diameter of more than 100 μm and 0 / m ² were used. went.

Example 6 A long-fiber nonwoven fabric was prepared in the same manner as in Example 1 except that polypropylene masterbatch pellets having a number of fish eyes having a diameter of more than 100 μm of 5 / m ² were used, and the evaluation thereof was carried out. went.

Comparative Example 1 A long fiber nonwoven fabric was prepared and evaluated in the same manner as in Example 1 except that an antibacterial agent having an average particle size of 1.5 μm was used.

Comparative Example 2 A long fiber nonwoven fabric was prepared and evaluated in the same manner as in Example 1 except that the content of the antibacterial agent was 0.05%.

Comparative Example 3 Example 1 except that the content of the antibacterial agent was 3.5%.
A long fiber non-woven fabric was prepared in the same manner as above and evaluated.

Comparative Example 4 A long fiber non-woven fabric was prepared in the same manner as in Example 1 except that polypropylene masterbatch pellets having the number of fish eyes having a diameter of more than 100 μm and 8 / m ² were used. went.

The results obtained are shown in Table 2.

[0033]

[Table 2]

As can be seen from Table 2, when the number of fish eyes in the masterbatch is in the range of 0 to 6 / m ² ,
Even when the antibacterial agent is mixed with the resin composition, clogging of the pack filter does not occur, the number of yarn breakages is small, and a long-fiber non-woven fabric containing the antibacterial agent can be stably produced. The non-woven fabric has excellent flexibility and high sterilization rate,
Has excellent antibacterial properties. On the other hand, when the average particle size of the antibacterial agent is high, the number of yarn breakages during melt spinning increases,
The spinnability deteriorates and the flexibility of the nonwoven fabric also deteriorates (Comparative Example 1). When the content of the antibacterial agent in the non-woven fabric is low, the number of fish eyes in the masterbatch is small, the dispersibility is good, the pack filter in the extrusion spinning machine is not clogged, and the spinnability is also excellent, Inferior in antibacterial property (Comparative Example 2).

On the contrary, when the content of the antibacterial agent in the non-woven fabric increases, the number of fish eyes in the masterbatch increases, clogging occurs in the pack filter, and the number of yarn breakage increases extremely, resulting in spinnability. Is deteriorated and flexibility is deteriorated (Comparative Example 3). Even if the content of the antibacterial agent is low,
When a master batch having a large number of fish eyes is used, filter clogging occurs, the number of yarn breaks increases, the spinnability is impaired, and the flexibility also deteriorates (Comparative Example 4).

[0036]

EFFECTS OF THE INVENTION The present invention has an effect of providing a method for producing a non-woven fabric which is free from clogging in a pack filter, has a low number of yarn breaks, is excellent in operability and spinnability, is flexible, and has excellent antibacterial properties. .

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Claims (1)

[Claims] 1. A resin composition comprising a thermoplastic olefin polymer containing 10 to 30% by weight based on the total weight of zirconium phosphate supporting silver having an average particle size of 0.1 to 1.0 μm, and a pigment. A resin composition containing a thermoplastic olefin-based polymer not contained is mixed and heated and melted to adjust the content of the silver-carrying zirconium phosphate to 0.1 to 3.0% by weight based on the total weight. Then, it is extruded and spun from a number of spinnerets, and the spun continuous filament filaments are drawn by an ejector while being drawn with high-speed and high-pressure air, opened, and collected to form a web on the support surface for collection. In the method for producing an antibacterial long-fiber non-woven fabric by subjecting this web to thermocompression bonding, the silver-supported zirconium phosphate-containing resin composition is subjected to T-die molding at 230 ° C. to obtain a thickness of 30. It is preferable to use a film having a dispersibility in the range of 0 to 6 per 1 m ^{2 of} fish eyes having a diameter of more than 100 μm when measured with a fish eye measuring machine. A method for producing an antibacterial long-fiber non-woven fabric characterized.